Peters



\No Model.)

- F. POSDIGK. STEAM ENGINE VALVE.

Patented June 1-2 Willi E55 E5.

flt/f f Am 8 9 7 Z 0 N NY PETERS PMloLhingnpher, wumn qm ac UNITEDSTATES PATENT OFFICE.

FREDERICK FOSDICK, FITCHBURG, MASSACHUSETTS, ASSIGNOR TC; THE FITGHBURGSTEAM ENGINE COMPANY.

STEAM-ENGINE VALVE.

SPECIFICATION forming part of Letters-Patent No. 279,484, dated June 12,1883.

Application filed January 2, 1883.

To all whom it may concern.-

Be it knownthat I, FREDERICK FosDIoK of Fitchburg, countyof WVorcester,State of assachusetts, have invented an Improvement in Steam-EngineValvesfof which the following description, in connection with theaccompanying drawings, is a specification, like letters on the drawingsrepresenting like parts.

My invention relating to a steam-engine is IO embodied in an engine ofthat class in which independent live-steam and exhaust valves controlthe flow of steam through the ports lead ing to each end of thecylinder.

The invention has for its object to enable I 5 what is known as thewrist-plate valve-gear to be employed in connection with pistonvalvescontrolling the admission of steam to the cylinder. With awrist-platevalve-gear, or valve-gear in which the movement of the 2o eccentric istransmitted to one pin of a disk or crank-arm of a rock-shaft having twoother pins or crank-arms connected with the valves at either end of thecylinder, the movements of the said valves are different, and they haveto be made independent of one another, so that when piston-valves areemployed the steam in the steam-chest, with the usual arrange ment,would press upon one side only of each independent piston-valve, whichwould thu, be unbalanced. The present invention consists, partly, inprovi ding a passage from the interior of the steamchest at one end ofeach of the said pistonvalves to the other end of the said valves,adding, if necessary, a bonnet or auxiliary cham her to receive thesteam from the said passage, and also to receive the said valves intheir travel outward from the steam-chest. The steam thus acts upon bothends of each of the said piston-valves with equal pressure, thusbalancing each valve independently. The eX- haust-valves may beconnected together and operated directly from an eccentric on theengine-shaft in the usual manner, thus both hav- 4 5 ing the samemovement, and bonnets are preferably provided to receive them in theiroutward travel. The live steam, acting as above described, upon bothends of the piston-valves, equalizes the temperature of the said valvesand the metal surrounding the valves through- (No model.)

out their length, thus causingtheir expansion to be more uniform, andtheir operation consequently improved.

The invention also consists in details of construction of some portionsof the engine, as hereinafter specified.

Figure 1 is a plan view of a portion of an engine embodying thisinvention. Fig. 2 is a side elevation thereof; Fig. 3, a horizontallongitudinal section thereof on line 00 m, Fig. 2, the valve-actuatingmechanism being shown in plan; and Fig. 4, a detail to be referred to.

The engine-cylinder a and its framework or bed-plate b may be of anyusual construc tion, the latter containing the main shaft 0, upon whichare mounted the eccentrics d e, for actuating the valves. The eccentricd, for actuating the live-steam or inlet valves, is preferably mademovable 011 the shaft, its position being controlled by a governor suchas described in Letters Patent N 0. 221,296, November 4, 187 9, grantedto me, to which reference may be had. The eccentric-rod f of the saideccentric (l is connected with a crank-pin, g, mounted on acrank fixedupon a rock-shaft, h, 7 5 provided with two other cranl -arms, i k, thecrank-pins. of which are connected by links 112 n with the val ve-rods p0, mounted in a guide, '1', upon the bed-plate I) of the engine. Thevalve-rod o is made tubular, and is connected with a pistoirvalve, o,controlling the flow of steam from the live-steam chest 8 into the port1, leading to one end of the cylinder (I, while the other valve-rod, 2,passes through. the tubular valve-rod o and the live-steam chest 8, andis 8 5 connected with the piston-valve-p, controlling the flow of steamfrom the said chest to the port t, leading to the other end of theenginecylin'der. The valves 0 thus connected with the cranksi 7c, havean independent movement, and are each acted upon at one side by thesteam in the chest .9. In order to equalize the steam-pressure upon eachof the said valves 0 p independently, passages 11. are provided leadingfrom the interior of the steam-chests to the other side of thecylindrical portionin which the valves 0'1) travel, bonnets o being inthis instance provided ateithcr end of the steam-chest to receive thesteam from the passages n, which thus acts equally upon both ends ofeach valve p, perfectly balancing the said valves and maintaining thetemperature sub stantially uniform throughout their entire length. Thevalve-rod p is extended beyond the piston-valve p, as shown at p",passing out through the bonnet v at that end of the chest The bonnets oare each provided with a tubular projection, 12, containing a hardbushing, oflwhich serves as a guide and support for the valvestems 0 p,the said tubular projection t being also provided with a gland orstuffingbox, 10, containing an annular chamber, which is intended to bekept filled with oil for the purpose of lubricating the rods where theytravel through the packing in the stuffingboX w and through the bushingso. A small St1llfil1g-bOX,l0 ,lS provided at the end of the stuflingboxw, so as to prevent the escape of oil from the chamber 10 along the rod0. A similar oil-receptacle, w, and packing-box 10", are provided at theend of the tubular rod 0, inclosing and lubricating the rod 1), whichpasses therethrough, as shown in Fig. 4.

The valves controlling the flow of the exhaust-steam from the ends ofthe cylinders through the ports t 1 into the cxhaustchcst R areconnected together upon a single rod, and are actuated by a singleeccentric-rod, c, and eccentric c. Bonnets v are preferably provided forthe said exhaust-Valve, having similar bushings and stuffing-boxes forguiding, supporting, packing, and lubricating their valvestems.

It is obvious that the chambered bonnets v might be omitted, thepiston-valves then traveling wholly in the chest, the ends of whichmight be closed by ordinary heads; but by the employment of the saidchambered bonnets it is possible for the ports 1 leading to the ends Iof the cylinder, to be made straight, as shown, without making thesteam-chest portion of the castin longer than the cylinder, and theshort est and most direct passage possible for the steanr'isthusafforded and the clearance reduced to a minimun.

I claim- 1. The combination, substantially as shown and described, ofthe cylinder a, steam-chest s, steanrports t 75, leading from thesteam-chest to the cylinder, the piston-valves 0 p, operatingindependently upon the ports t i, re speetively, and the passages u a,connecting the steam-spaces on opposite faces of the pistonvalves tobalance said valves, as and for the purpose specified.

2. The combination, substantially as shown and described, of thevalve-actuating eccentric and oscillating wrist-pins operated thereby,with the balanced piston-valves connected with and independentlyactuated by different ones of said wrist-pins, as and for the purposeset forth.

8. The combination, substantially as shown and described, of thepiston-valves with a steam-chest, the external bonnets, o, communicatingwith said chest, and into which the valves move, and passages u,communicating between the steam-chest and said bonnets, and therebyadmitting steam to both ends of and thereby balancing the valves, as andfor the purpose specified.

4. The engine cylinder, steam chest, and independent piston-valves, onehaving a tu bular rod through which the rod of the other valve operates,combined with valve-actuating mechanism connected with the said rods,sub stantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

FREDERICK FOSDIGK.

\Vitnesses: v 'Jos. P. LivnRMoRn, \V. H. SIGSTON.

